@NehaOza,
Regarding permissions, the
Files.ReadWrite permission will cover just about everything you want to do with a Workbook. You just need to make sure the Workbook is shared between the 3 users (ex. it resides on a shared/group OneDrive).
As far as multiple editors at one time, I believe it's possible since you can accomplish the same thing via the browser. However, I haven't seen any specific points about this in the Graph v1.0 reference. You might just have to try it.
Cheers,
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Eric Wilson
Director, Integrations and Enablement
Blue Prism Digital Exchange
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