If you click on the "Materials" section on the left side menu, you will be sent to the list of all materials that have been used in your work orders.
Here you can also filter the used materials by:
Work order number;
Date the material was added at;
Client or Object;
App user who used the material;
Equipment the material was assigned to (only if Equipment add on is enabled)
Export materials button will export the list with selected filters into an Excel file. Click the button, select what information needs to be exported and click green "Export" button. The exported data file will be found in the inbox.