Is there an association between the entity of your datagrid and the account? If yes, you could just use this in your xpath and compare it to the current user.
If not, Austin's solution should work for you.
Hi Xue,
If you are just storing the accounts full name then you would have to use the microflow data source. Here is an example microflow that will retrieve records based on an accounts full name.
I retrieve the current users account, then I do a retrieve for the list that I want to show in the datagrid. My retrieve has one constraint that is matching the attribute on the list that is storing the accounts to the account objects full name.
Hope this helps!