There is currently no way to see the current page in the Figma UI when the Pages section is collapsed.
When you have a lot of pages and/or you have similar pages this gets confusing. Keeping the whole Pages section open is often a waste of valuable vertical space. Space that’s very useful for the Layers section.
Maybe Figma can show the current page name somewhere in the UI?
Maybe above the current file name?
Or somehow in the Pages section? (not the prettiest solution)