I want to have a list of all revisions of a member.
Also for branches.
I know how to do for subprojects, but didn't find a solution for Members
I would go with the si rlog command, as you can change the layout quite easy.
The following example shows just the revision numbers
si rlog --format="{revision}\n" --noHeaderFormat --noTrailerFormat member
The same result gives
si viewhistory --fields=revision member
Review also the usage page for both commands.
And of course the above commands imply that you are working in the correct sandbox. Otherwise you'd need to specify the project.