By memory care I presume you mean your father is in Alzheimers/Dementia/Parkinsons or similar condition care. My sympathies - been in that situation myself.
If leather, there are specific stain removers for that at box stores and leather shops.
If fabric, unless deeply embedded in the cushioning batting or foam, a pet foaming carpet/furniture cleaner should do it - be sure says safe for the material you are using it on. Woolite and Clorox and Arm & Hammer and others make it - spray foam that sanitizes and lifts the staining material, then you vacuum off when dry.
If smells significantly not, there are pet urine cleaning liquids you could use first - mostly a odor and bacterial killer, or a good dose of spray Lysol - then finish up with the foaming pet stain cleaner.
Professionally, steam carpet cleaner who does furniture cleaning who should pre-treat it with a stain and odor removal chemical.
Course, either way the cleaning has to get as deep into the cushioning material as the urine got - likely an inch or so in batting, could be several inches if foam.
Future prevention - waterproof mattress pad or crib waterproof pad that goes up the back and and arms too (so larger than a normal crib pad) under a washable absorbent throw cover or quilt or blanket that will absorb and limit travel of the liquid - plus of course adult diapers.
If in a paid care facility (rather than home care) they should have taken preventative measures before this - both to protect against the chair becoming a biologic grundge farm, and with respect to incontinence, so I would talk to the management i that is the case.
