Two common used methods to find a subview of any given (private) class inside some view hierarchy, or just dump all views in a pretty-print format using NSLog.

UIViewHierarchy.h

//
//  UIViewHierarchy.h
//
//  Created by Denis Gryzlov on 09.08.13.
//  Copyright (c) 2013 Armada. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIView (Hierarchy)

- (UIView *) findSubviewOfClass:(Class)someClass;
- (void) dumpViewHierarchy;

@end

UIViewHierarchy.m

//
//  UIViewHierarchy.m
//
//  Created by Denis Gryzlov on 09.08.13.
//  Copyright (c) 2013 Armada. All rights reserved.
//

#import "UIViewHierarchy.h"

@implementation UIView (Hierarchy)

- (UIView *) findSubviewOfClass:(Class)someClass {
    if ( [self isMemberOfClass:someClass] ) {
        return self;
    } else {
        for ( UIView *view in self.subviews ) {
            UIView *insideView = [view findSubviewOfClass:someClass];
            if ( insideView != nil ) {
                return insideView;
            }
        }
    }

    return nil;
}


- (void) dumpViewHierarchy {
    int level = 0;
    [self _logViewHierarchyWithLevel:&level];
}

- (void) _logViewHierarchyWithLevel:(int *)level {
    NSMutableString *paddingStr = [NSMutableString new];
    for (int i = 0; i < *level; i++) {
        [paddingStr appendString:@"   "];
    }
    
    NSLog(@"%@%@", paddingStr, self);
    
    *level = *level + 1;
    
    for ( UIView *subview in self.subviews ) {
        if ( subview.subviews.count > 0 ) {
            [subview _logViewHierarchyWithLevel:level];
        }
        else {
            NSLog(@"%@> %@", paddingStr, subview);
        }
    }
}

@end

Output example:

<UIWindow: 0x210e9cb0; frame = (0 0; 768 1024); tag = 5002; layer = <UIWindowLayer: 0x210efef0>>
    <UIView: 0x210e5cb0; frame = (0 0; 768 1024); transform = [0, -1, 1, 0, 0, 0]; autoresize = W+H; layer = <CALayer: 0x210c4370>>
       <UIView: 0x210841b0; frame = (0 0; 1024 768); autoresize = W+H; layer = <CALayer: 0x210f02a0>>
          <MPVideoContainerView: 0x1fd5bb50; frame = (0 0; 1024 768); autoresize = W+H; gestureRecognizers = <NSArray: 0x210f09b0>; layer = <CALayer: 0x1fd5bc00>>
             <MPVideoBackgroundView: 0x1fd5b5e0; frame = (0 0; 1024 768); autoresize = W+H; tag = 1000; layer = <CALayer: 0x1fd5b6b0>>
             > <UIView: 0x1fd5b8f0; frame = (0 0; 1024 768); clipsToBounds = YES; opaque = NO; autoresize = W+H; layer = <CALayer: 0x1fd5b950>>
          > <UIView: 0x1fd5b4d0; frame = (0 0; 1024 768); autoresize = W+H; tag = 1001; layer = <CALayer: 0x1fd5b530>>
          > <MPVideoView: 0x210c8210; frame = (0 0; 1024 768); autoresize = W+H; userInteractionEnabled = NO; tag = 1002; layer = <AVPlayerLayer: 0x210c6a30>>