hii corina lopez,
as i understand your question you want a microflow that take requestername and return you the data from support contact on the behalf of requester string input parameter but in support contact table you have put assigneeId and userId and also have a column name in which is used for save fullname of user.
so to achieve it just make you query with join clause in OQL
JOIN condition $obj/tick/tick_suppport_contact_association/support_contact
join your ticket and support contact and fetch record with where condition like
$tickObj/matchingColumnNameInSupportContactTable = $support_contactObj/matchingColumnNameInTicketTable