Has:
"One of us has to leave, we should let go."
Have been:
"I have been starting to love my mother, until now."
So definitely:
Has is used for a singular noun or pronoun, followed by a "to + verb" or another noun or pronoun, etc. and has is used for 3rd person subjects like the one above.
Have been is for an action, or a verb on which the subject is still continuing to do it or it is already done.
