Fragments within Fragments

Nested fragments are not currently supported. Trying to put a fragment within the UI of another fragment will result in undefined and likely broken behavior.

Update: Nested fragments are supported as of Android 4.2 (and Android Support Library rev 11) : http://developer.android.com/about/versions/android-4.2.html#NestedFragments

NOTE (as per this docs): "Note: You cannot inflate a layout into a fragment when that layout includes a <fragment>. Nested fragments are only supported when added to a fragment dynamically."

Nested fragments are supported in android 4.2 and later

The Android Support Library also now supports nested fragments, so you can implement nested fragment designs on Android 1.6 and higher.

To nest a fragment, simply call getChildFragmentManager() on the Fragment in which you want to add a fragment. This returns a FragmentManager that you can use like you normally do from the top-level activity to create fragment transactions. For example, here’s some code that adds a fragment from within an existing Fragment class:

Fragment videoFragment = new VideoPlayerFragment();
FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
transaction.add(R.id.video_fragment, videoFragment).commit();

To get more idea about nested fragments, please go through these tutorials
Part 1
Part 2
Part 3

and here is a SO post which discuss about best practices for nested fragments.