How can I create a view like background view of UIActionSheet in iOS?

The view below the UIVisualEffectView (the one with the red arrow in the question) contains a layer which has a CAFilter "overlayBlendMode" (private class) set as compositing filter. It's applied over the layer behind it. In the screenshot below I changed the background colour of the _UIDimmingKnockoutBackdropView to green and the filter is applied over that.

Private method

To create the same effect, you need to put a white opaque view below the UIVisualEffectView and apply a CAFilter to it:

CAFilter *filter = [CAFilter filterWithName:@"overlayBlendMode"];
[[contentView layer] setCompositingFilter:filter];

Since CAFilter is private, we need a header for it:

#import <Foundation/Foundation.h>

@interface CAFilter : NSObject <NSCoding, NSCopying, NSMutableCopying> {
    void * _attr;
    void * _cache;
    unsigned int  _flags;
    NSString * _name;
    unsigned int  _type;
}

@property BOOL cachesInputImage;
@property (getter=isEnabled) BOOL enabled;
@property (copy) NSString *name;
@property (readonly) NSString *type;

// Image: /System/Library/Frameworks/QuartzCore.framework/QuartzCore

+ (void)CAMLParserStartElement:(id)arg1;
+ (BOOL)automaticallyNotifiesObserversForKey:(id)arg1;
+ (id)filterTypes;
+ (id)filterWithName:(id)arg1;
+ (id)filterWithType:(id)arg1;

- (void)CAMLParser:(id)arg1 setValue:(id)arg2 forKey:(id)arg3;
- (id)CAMLTypeForKey:(id)arg1;
- (struct Object { int (**x1)(); struct Atomic { struct { int x_1_2_1; } x_2_1_1; } x2; }*)CA_copyRenderValue;
- (BOOL)cachesInputImage;
- (id)copyWithZone:(struct _NSZone { }*)arg1;
- (void)dealloc;
- (BOOL)enabled;
- (void)encodeWithCAMLWriter:(id)arg1;
- (void)encodeWithCoder:(id)arg1;
- (id)initWithCoder:(id)arg1;
- (id)initWithName:(id)arg1;
- (id)initWithType:(id)arg1;
- (BOOL)isEnabled;
- (id)mutableCopyWithZone:(struct _NSZone { }*)arg1;
- (id)name;
- (void)setCachesInputImage:(BOOL)arg1;
- (void)setDefaults;
- (void)setEnabled:(BOOL)arg1;
- (void)setName:(id)arg1;
- (void)setValue:(id)arg1 forKey:(id)arg2;
- (id)type;
- (id)valueForKey:(id)arg1;

// Image: /System/Library/PrivateFrameworks/PhotosUICore.framework/PhotosUICore

+ (id)px_filterWithPXCompositingFilterType:(int)arg1;

@end

The result:

The view I've created prints the same compositing filter as Apple used:

Workaround

As a workaround you can create an image of the view on the background and a image of the white view and apply the overlay blend mode with that. This results in a comparable result as using the private class.

Example:

    UIImage *image = [self imageForView:contentView];
    UIView *superview = [contentView superview];

    [contentView setHidden:YES];
    UIImage *backgroundImage = [self imageForView:superview];
    CGImageRef imageRef = CGImageCreateWithImageInRect([backgroundImage CGImage], [contentView frame]);
    backgroundImage = [UIImage imageWithCGImage:imageRef]; 
    CGImageRelease(imageRef);
    [contentView setHidden:NO];

    CIFilter *filter = [CIFilter filterWithName:@"CIOverlayBlendMode"];
    [filter setValue:[backgroundImage CIImage] forKey:kCIInputImageKey];
    [filter setValue:[image CIImage] forKey:kCIInputBackgroundImageKey];
    [contentView setBackgroundColor:[UIColor colorWithPatternImage:[UIImage imageWithCIImage:[filter outputImage]]]];
}

- (UIImage *)imageForView:(UIView *)view
{
    UIGraphicsBeginImageContextWithOptions([view bounds].size, [view isOpaque], 1.0);
    [[view layer] renderInContext:UIGraphicsGetCurrentContext()];

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return image;
}

Result: