Billable or not is a Status. Example: You charge me actual times (billable) or a Monthly Contract Fee. Fee = the actual time is not billable to me, since it isn't what you use to Charge me.
QB Online doesn't job track payroll costs, so actual time spent as a Cost against the revenue in any period is not something you can report. You can report on Time Spent against the Revenue stream for a period, if you are using Timesheets.
Example:
X gross revenue divided by Hours spent for that customer = $/hr = Labor effective revenue. You can compare that to Payroll $/hr across the entire business. Compare them to get your Labor Utilization = for every direct hour, it costs X and we gross Y, so your per hour net is Z.