You might be familiar with Rational Quality Manager (RQM) REST API's to query your artifacts. The RQM Reportable REST API allows a user to perform CRUD type operations on test resources via XML sequences to the RQM server. This article describes about how to manipulate resources like (test case, test execution record, test results, etc..) in RQM using REST API
I can help you! There are Cheat Sheets available for a few RQM REST URL's, but not specifically for this query. You are looking for help with constructing a REST URL for this query.
Below you'll find a Sample REST URL to perform the GET operation to query Testcase execution Record (TCER) filtered for a specific Testcase.
Choose to use the following URL. which has been tested and working
This gives the TCER's filtered using a Testcase ID from REST Client.
I hope you find this helpful!