It's likely a combination of several components, because there are a few tasks here:
- Search for each user that is needed by entering a partial or full name
- Select the correct user from a list of options
- Collect the selected users for the next task
There are two products that do this pretty well, Microsoft Office (Email) and Microsoft Teams. Here's how they do this workflow:
- User initiates a new task (email or chat). A "To" box appears to let the user know that names are the expected value.
- User types part of a name into what is essentially a Search box. The system returns a brief list of names, pictures, and other information that allows the user to make the right decision. NOTE: The system is optimized to return suggestions based on relevance to the user, often based on history with the potential recipient.
- User selects the correct option, which becomes a chip in the Search box. It can be removed but not edited.
Repeat steps 2 - 3 until all desired recipients are selected.
Finish the task that will engage the selected entities.
This requires the user to know at least partial names of the records they're searching for. It doesn't cover use cases like "add all people on Mark Farrington's team" or "Add all quality assurance engineers". If your user might not know names, you might have to allow searching/filtering with other criteria.