Problem with losing Timelines! Help!

Hi, I'm using Premiere Pro 2022 for Mac running Big Sur 11.7.8 and I have several sequences/timelines. I don't know what I did but suddenly I could only see the timelines themselves but not the source and destination video. When I went to Windows/Workspaces/Editing it revealed the video windows, HOWEVER it ONLY showed the current timelines and there was no other way to access the other timelines, even if I went to Window/Timelines! It only showed 1! Help! What happened and what do I do to get all the Timelines/Sequences visible and accessible??