If my car was parked in the gated parking garage of my apartment complex and another car hit mine, does the apartment complex assume any liability?

Although you should check with your landlord to determine if the apartment complex will accept liability, it is unlikely that the apartment complex will accept liability.
Your property damage claim cost of repairs to your vehicle should be filed with the at-fault driver's insurance carrier.  If the at-fault party does not have insurance or his/her identity is unknown, you can file your property damage claim with your auto insurance company if you have uninsured motorist coverage, and have your car repaired.
If you don't have uninsured motorist coverage and the at-fault party does not have insurance, your only recourse is to sue the at-fault party for negligence.  Depending on the amount of damage to your car, you might be able to file your lawsuit in Small Claims Court.  After obtaining a judgment in Small Claims Court, you can enforce the judgment with a wage garnishment.  Your damages monetary compensation you are seeking to recover in Small Claims Court should include your property damage cost of repairs to your vehicle and court costs.  Court costs would include the court filing fee and process server fee.