Go to User → List user to do a search. When searching for a user in the console you can use the following customer information:
e-mail
UserID
Name
Country
Tags
TransactionID
For the more advanced searches, you can combine the attributes to search between by e.g.
Select the country in the dropdown to the right
In the search field type DE AND tags:VIP
Now the results will be for users with country DE and the VIP tag