How do I make a TOC at the top of a tutorial page in Wolfram Workbench?

These type of TOC cells as shown in 'tutorial/ComplexPolynomialSystems#934984887', here's an explanation that doesn't use the workbench:

titles = {"Section A", "Section B", "Section C", "Section D"};

Clear[f]; 
f[s_] := TemplateBox[{Cell[
    s], (SetSelectedNotebook[EvaluationNotebook[]]; 
    NotebookLocate[s] &), upChevron, downChevron}, "MyTOCIcon", 
  BaseStyle -> {"MyTOC"}];
grid = Partition[f /@ titles, UpTo[2]];
CellPrint@Cell[BoxData[GridBox[grid]], "TutorialJumpBox"]
cs = Cell[#, "Section", CellTags -> {#}] & /@ titles;
Scan[CellPrint, cs]

For this to work you need to run these styling commands to define "MyTOC" and "MyTOCIcon" (I added a few others) and the chevron icons:

SetOptions[InputNotebook[], 
  StyleDefinitions -> 
   Notebook[{Cell[
      StyleData[
       StyleDefinitions -> 
        FrontEnd`FileName[{"Wolfram"}, "Reference.nb"]]], 
     Cell[StyleData["Input"], CellContext -> Notebook], 
     Cell[StyleData["Output"], CellContext -> Notebook], 
     Cell[StyleData["TutorialMoreAboutSection"], 
      CellGroupingRules -> {"SectionGrouping", 30}], 
     Cell[StyleData["RelatedTutorialsSection"], 
      CellGroupingRules -> {"SectionGrouping", 30}], 
     Cell[StyleData["TutorialRelatedLinksSection"], 
      CellGroupingRules -> {"SectionGrouping", 30}],
     Cell[StyleData["MyTOC"], Editable -> False, 
      FontFamily -> "Arial", FontSize -> 12, 
      FontColor -> GrayLevel[0.360784]], 
     Cell[StyleData["MyTOCIcon"], 
      TemplateBoxOptions -> {DisplayFunction :> (TagBox[
            DynamicBox[
             If[CurrentValue["MouseOver"], 
              ButtonBox[
               RowBox[{#4, Cell["  "], 
                 StyleBox[#, 
                  FontColor -> 
                   RGBColor[0.854902, 0.396078, 0.145098]]}], 
               ButtonFunction -> #2], 
              ButtonBox[RowBox[{#3, Cell["  "], #}], 
               ButtonFunction -> #2]]], 
            MouseAppearanceTag["LinkHand"]] &)}, 
      ButtonBoxOptions -> {BaseStyle -> {FontColor -> 
           GrayLevel[0.360784], "Link"}}]
     }, Visible -> False, 
    StyleDefinitions -> "Default.nb"]];

upChevron = 
  GraphicsBox[
   TagBox[RasterBox[
     RawArray[
      "UnsignedInteger8", {{{128, 128, 128, 32}, {128, 128, 128, 
         16}, {128, 128, 128, 0}, {128, 128, 128, 0}, {128, 128, 128, 
         0}, {128, 128, 128, 0}, {128, 128, 128, 0}, {128, 128, 128, 
         48}}, {{128, 128, 128, 48}, {128, 128, 128, 239}, {128, 128, 
         128, 112}, {128, 128, 128, 0}, {128, 128, 128, 0}, {128, 128,
          128, 16}, {128, 128, 128, 143}, {128, 128, 128, 
         239}}, {{128, 128, 128, 0}, {128, 128, 128, 64}, {128, 128, 
         128, 223}, {128, 128, 128, 191}, {128, 128, 128, 112}, {128, 
         128, 128, 223}, {128, 128, 128, 191}, {128, 128, 128, 
         32}}, {{128, 128, 128, 32}, {128, 128, 128, 16}, {128, 128, 
         128, 16}, {128, 128, 128, 175}, {128, 128, 128, 255}, {128, 
         128, 128, 127}, {128, 128, 128, 0}, {128, 128, 128, 
         48}}, {{128, 128, 128, 48}, {128, 128, 128, 239}, {128, 128, 
         128, 112}, {128, 128, 128, 0}, {128, 128, 128, 16}, {128, 
         128, 128, 16}, {128, 128, 128, 143}, {128, 128, 128, 
         239}}, {{128, 128, 128, 0}, {128, 128, 128, 64}, {128, 128, 
         128, 223}, {128, 128, 128, 191}, {128, 128, 128, 112}, {128, 
         128, 128, 223}, {128, 128, 128, 191}, {128, 128, 128, 
         32}}, {{128, 128, 128, 0}, {128, 128, 128, 0}, {128, 128, 
         128, 16}, {128, 128, 128, 175}, {128, 128, 128, 255}, {128, 
         128, 128, 127}, {128, 128, 128, 0}, {128, 128, 128, 
         0}}, {{128, 128, 128, 0}, {128, 128, 128, 0}, {128, 128, 128,
          0}, {128, 128, 128, 0}, {128, 128, 128, 16}, {128, 128, 128,
          0}, {128, 128, 128, 0}, {128, 128, 128, 0}}}], {{0, 8}, {8, 
       0}}, {0, 255}, ColorFunction -> RGBColor], 
    BoxForm`ImageTag["Byte", ColorSpace -> "RGB", 
     Interleaving -> True, Magnification -> Automatic], 
    Selectable -> False], DefaultBaseStyle -> "ImageGraphics", 
   ImageSizeRaw -> {8, 8}, PlotRange -> {{0, 8}, {0, 8}}, 
   ImageSize -> {8, 9}];

downChevron = 
  GraphicsBox[
   TagBox[RasterBox[
     RawArray[
      "UnsignedInteger8", {{{229, 95, 28, 32}, {229, 95, 28, 
         16}, {229, 95, 28, 0}, {229, 95, 28, 0}, {229, 95, 28, 
         0}, {229, 95, 28, 0}, {229, 95, 28, 0}, {229, 95, 28, 
         48}}, {{229, 95, 28, 48}, {229, 95, 28, 239}, {229, 95, 28, 
         112}, {229, 95, 28, 0}, {229, 95, 28, 0}, {229, 95, 28, 
         16}, {229, 95, 28, 143}, {229, 95, 28, 239}}, {{229, 95, 28, 
         0}, {229, 95, 28, 64}, {229, 95, 28, 223}, {229, 95, 28, 
         191}, {229, 95, 28, 112}, {229, 95, 28, 223}, {229, 95, 28, 
         191}, {229, 95, 28, 32}}, {{229, 95, 28, 32}, {229, 95, 28, 
         16}, {229, 95, 28, 16}, {229, 95, 28, 175}, {229, 95, 28, 
         255}, {229, 95, 28, 127}, {229, 95, 28, 0}, {229, 95, 28, 
         48}}, {{229, 95, 28, 48}, {229, 95, 28, 239}, {229, 95, 28, 
         112}, {229, 95, 28, 0}, {229, 95, 28, 16}, {229, 95, 28, 
         16}, {229, 95, 28, 143}, {229, 95, 28, 239}}, {{229, 95, 28, 
         0}, {229, 95, 28, 64}, {229, 95, 28, 223}, {229, 95, 28, 
         191}, {229, 95, 28, 112}, {229, 95, 28, 223}, {229, 95, 28, 
         191}, {229, 95, 28, 32}}, {{229, 95, 28, 0}, {229, 95, 28, 
         0}, {229, 95, 28, 16}, {229, 95, 28, 175}, {229, 95, 28, 
         255}, {229, 95, 28, 127}, {229, 95, 28, 0}, {229, 95, 28, 
         0}}, {{229, 95, 28, 0}, {229, 95, 28, 0}, {229, 95, 28, 
         0}, {229, 95, 28, 0}, {229, 95, 28, 16}, {229, 95, 28, 
         0}, {229, 95, 28, 0}, {229, 95, 28, 0}}}], {{0, 8}, {8, 
       0}}, {0, 255}, ColorFunction -> RGBColor], 
    BoxForm`ImageTag["Byte", ColorSpace -> "RGB", 
     Interleaving -> True, Magnification -> Automatic], 
    Selectable -> False], DefaultBaseStyle -> "ImageGraphics", 
   ImageSizeRaw -> {8, 8}, PlotRange -> {{0, 8}, {0, 8}}, 
   ImageSize -> {8, 9}];

The table of contents is generated automatically by Workbench 3.0, which you need to request from Wolfram because it hasn't been officially released.

Workbench will generate a link for each "Section" cell that you include in your tutorial.

Edit: If you have Workbench 3 but don't want to use it directly, you can load the DocumentationBuild package that comes with it and run the ConvertNotebook function on an authoring notebook created using the DocumentationTools palette.