I know of 2 Filipinos , one a cleaner in an office and one, a maid ,who were brought in by a so called Aunt, who is married or with a Qatari sponsor and they have brought her in. There are other maids from the same source as well.they have to pay them Qr5000 riyals a year to be sponsored in Qatar by them and go and find own work.
She

They have NOC to say they can work for someone else and they go and find 4 or 5 families to get enough money to pay the Qr5000 fee
This does happen a lot here in Doha.
How legal it is I don't know, but it is happening.
This is first hand knowledge