Getting Xcode drag and drop to work

Hello everyone, I've been a developer in various languages for some years now, web and desktop alike, and got to see quite some IDEs -- Eclipse, Code::Blocks, Visual Studio...The one IDE that always eluded my comprehension was Xcode, and so I found myself using Xamarin framework if I wanted to create iOS compatible apps. I am, however, unwilling to let my Mac just catch dust -- it simply must be possible to get Xcode to work as advertised, no? This user guide helped me, however it's not really up to date by programmer standards (hell, anything older than 1 year rarely is 100 % up to date by programmer standards...), so some things might have changed since the last update of the user guide (i use Xcode 10 as opposed to Xcode 8 in the post). My problem is the adding of UI components (so the very basis of Xcode). Supposedly, you can pull your mouse on a component, lock it down, move to an unlabeled button next to the component you want to add it to and then release the mouse... and that's it. Simple enough, right? I went to the table which lists the app outline. Expanded View Controller Scene, then View Controller, and there I found the View, my target. So far, so good. Then I stopped interacting with the editor group and wanted to move to the library group which supposedly should be on the same level as the navigator, editor and inspector groups. It wasn't there. Okay. Probably just hidden? I started searching for options to show the library group. I didn't find any. However, I found a library button in the toolbar. And therein the component I was looking for. Bingo! So, now I pulled the mouse to my VO position, checked it was actually there, locked it down, moved to the unlabeled button next to the View (I made sure "it was the right View - there's also a menu item called view, but that's not what I wanted), and then released the mouse... and... nothing happened. Dear AppleVis community, please help a frustrated be-developer out. Is it a) possible to show the library group or is the library button in the toolbar the only way in newer Xcode versions? b) Any ideas why my drag and drop didn't work? Thanks in advance.^ EDIT: So, apparently the library in the toolbar is right: Interact with the toolbar, click on the library button, enter some text to filter the results, find your desired result in the scroll area, now cmd + c for copy, press escape, go to your document outline, find the right view or whatever, and cmd + v -- done. Or so I thought at least... After some more testing... I don't get it to work. Drag and drop has zero effect whatsoever. And copy/paste works, but always replaces the control I'm pasting on. Can anyone help me out?