You can see the full list of spaces you belong to in the web app.
To see the list of space memberships:
Log in into the web app.
Click your avatar in the top-right corner and select "Account settings".
Click Spaces in the navigation bar. The Space Memberships page will open.
From here, you can see the full list of all spaces you belong to. You can then choose to go to or leave a specific space by clicking the triple-dot icon.