You can open "Select office" form clicking on the icon near Office's drop-down list when you create a new task or project. This form looks the following way:
If you wish to find the office using a search bar, be sure that the column which contains the information you're looking for is enabled in the table. This form was created to make your work with offices more easy and comfortable. Start typing the office name, city or any other office-related information in the search box and you'll see all appropriate results immediately:
Also you can add a new office to the system from here or edit an existing one. "Export" button allows you to export existing offices to any format from the list:
Click "View Permissions" button to see what actions are allowed to you:
Tip: "Office can be changed in future when the task/project is already created."