I am working on one app, which communicates with LinkedIn. I am using official PHP LinkedIn API (REST API) to get list of my connections. But my question is, if it's possible to get also group name or tag name where my connection belongs (for example classmates, workmates, close friends etc.) ?
At this moment, the Connections API doesn't expose any of the functionality or metadata provided in your "Contacts" page (this includes data like tags or groups of connections).
For a current list of supported use cases and fields related to the Connections API, please refer to this page: https://developer.linkedin.com/documents/connections-api