The way you are trying to implement this is not really the best way in my opinion. You are thinking about a front-end implementation like if it's a server side service. Two technical ideas to make your need possible:
1- You should look at the WTCollection documentation as ptc has rewritten all it's query API to accept single object and collection of object at the same time. So not sure about the where used but you can find navigateUsageLink version that accepts a collection of objects and returns a WTList of results.