Hello trinaz.
I have to ask. Why?
If you only have 1 user account displayed, then you can't log into the other accounts, which begs the question why you don't just delete them (during deletion, you can opt to save files that are stored in them).
If you do not want people accessing the Admin accounts, give them passwords and/or change them to limited accounts. Or you could always delete them.
I do not belive this can be done through normal means, meaning without installing some kind of customization software.