High CPU Usage on certain query when changing DB Compatibility Level
On higher compatibility level SQL Server starts to use new cardinality estimator which leads to different execution plan. Sometimes this new plan may be less efficient but it doesn't mean that new cardinality estimator works worse. Usually it means you need to review your query and probably adjust your indexes or statistics because probably your original plan was far away from optimal too. You attached estimated execution plans to question description. To find out the root reason of the issue you need to compare actual plans.
You can use traceflag or hint to force SQL Server to use old cardinality estimator for your query: OPTION (USE HINT ('FORCE_LEGACY_CARDINALITY_ESTIMATION'))