A timeshare is an asset. Being an asset it must be listed on your bankruptcy petition. If it has value above the amount of the allowed exemptions then the trustee will take the interest in the timeshare, sell it, and uses the money to pay your creditors.
But, as a practical matter, most timeshares have little market value. In most cases, you can document a very low value for the timeshare. The way to do this is to find a timeshare broker. The broker can supply you with the recent sales history of comparable timeshares. Use this documentation to show the bankruptcy that your timeshare has little or no value.
That way the trustee abandons it. You keep it.