The following is my understanding of Perception checks to see/locate creatures that are hiding based off this post.
As a hide action, you make a Dexterity (Stealth) check. As long as you remain in hiding, your check must beat the opposing creature's Passive Wisdom (Perception) score. If you are hidden, you are unseen and unheard. Thus the creature does not know your exact location but may know a general direction based on the last time you were not hidden.
In combat if you are hidden from a creature and "come out of hiding and approach a creature, it usually sees you." To remain hiding you must remain unseen and unheard. The rules for Hiding says that "under certain circumstances, the Dungeon Master might allow you to stay hidden as you approach a creature that is distracted."
I would say as soon as you stepped out from behind total cover you may have just become seen and loose being hidden. To determine whether the creature sees you or is distracted I would role an Active Wisdom (Perception) check against the Dexterity (Stealth) check you made when you took the Hide action.
On the flip side, an unseen creature and a hidden creature is two different things.
A unseen creature, such as one in "darkness, opaque fog, dense foliage," or invisibility has advantage on attacks against creatures that can't see it, and those creatures have disadvantage on attacks against it. You can determine the location of an unseen creature through noise, smell, or other senses.
A hidden creature can't be directly targeted. The attacker must choose a space it thinks the creature is and because the creature is also unseen the attack is made with disadvantage.
In conclusion, I would say the DM can roll or have you roll an optional Active Wisdom (Perception) check when a hidden creature comes out of hiding or does something to give away its position to determine if others are distracted or not. Also, if a creature is actively searching for a hidden creature using the Search action, use an Active Wisdom (Perception) check. In all other cases use the creature's Passive Wisdom (Perception) check opposed to the Dexterity (Stealth) check made when the Hide action was taken.
If an unseen creature does not take the Hide action, its location can be deduced through the other senses without taking additional actions.