How does car leasing works in KSA ?

In what way exactly?

You lease a car from a rental agency, pay installments and return it to them.  Maintenance is their headache.

If you do it via a bank than that is not a lease per se but a loan that you pay off and end up owning the car.  Maintenance and documentation is your headache.

Going from your earlier post, if you want to return a leased (rented) car, they will charge you early contract termination fees.

Price it out first. Have your company send its "public relations" guy ("PRO"), a runner/ paralegal really, to visit in person.  Otherwise, you'll get hit with the inflated "Western" price.

But look at reputable rent-a-car agencies, and consider renting on a month-to-month basis with no milage restrictions.

When you come to a deal, the rent-a-car company will ask for your passport and home state driver's license (I also have a AAA International Driver's License - its about 10-15 bucks these days - just in case the company decides it still needs that as part of the documentation).  Note:  if you already have an Iqama, the guy at the counter of the rent a car company may conflate the rules and insist that you have a KSA driver's license (even though you are not buying or long term leasing - the month-by-month arrangement is, by definition, short term).