Ummi Aiman Izani Thanks for posting your question in Microsoft Q&A. Currently, you can assign groups (built-in or custom groups) to the products and users in that group (associate members with the group) can access all APIs and Operations belong to that product. Unfortunately, you cannot restrict access only to certain operations like described above.
So, the workaround is to define own APIs with specific operations and expose it via a product. For example, you can define ProductA with API1 -> Operation1, ProductB with API2 -> Operation2, ProductC with API3 -> Operation1, Operation2 and then assign groups to the product like group1 -> Product1, group2 -> Product2 etc.
I agree this would be a great feature request, and other customers have shared similar feedback: https://feedback.azure.com/d365community/idea/ba08e6f3-ff24-ec11-b6e6-000d3a4f0858#comments in the azure feedback. Please feel free to upvote the idea too or share your feedback and I will also pass it along internally to our product team.
I hope this helps and let us know if you have any questions.
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