If is it unrated yes you can have 'take-back' moves not sure how many moves but in rated game no.
Conditional moves (undoing)

Unless the game was started in TAKEBACK mode, there is no mechanism provided by the system to undo moves. If no captures are involved, you could simply move the pieces around until you get back to where you were.
Otherwise, start a new (possibly unrated) game and step through it, both of you making the same moves up to the point where the current one 'went wrong'.

A few pointers to get you started ...
Takeback was extensively discussed before it was introduced on this site e.g.
As a safeguard to avoid it being abused (e.g. being able to pressure anyone into agreeing to a takeback, or making up excuses), it was provided exclusively in unrated games, and only when specified at the outset.
I am new to chess.com and have discovered what conditional moves achieves. But only after playing with it and finding three unintended moves have taken place overnight! My playing partner understands (my stupidity) and we want to move the game back three moves and pick up again from there. Is this possible?
DaveyKnight