I am not sure if this is 100% what the OP needed, but for anyone reading this in 2024 (Zotero 7.x), I had success with the following steps: - In word, "Add/Edit citation" - Click on the Z icon in the Zotero input field, then click "Classic View" - Click the "Multiple Sources..." button in the bottom right - Voila, you can add as many sources as you want by selecting them in the browser and clicking the "right arrow" button that adds them to the right area. (Enable recursive collections if you want to see items from subcollections as well.)
You don't need to use the classic view (and shouldn't rely on that). In Zotero 7, you can just select multiple items in Zotero itself. When you click Add/Edit Citation in Word, all the selected items will appear under a "Selected Items" section in the citation dialog. You can then use Shift-down-arrow or shift-click on the bottom one to select them all, and then press Enter/Return to add them as citations.
- In word, "Add/Edit citation"
- Click on the Z icon in the Zotero input field, then click "Classic View"
- Click the "Multiple Sources..." button in the bottom right
- Voila, you can add as many sources as you want by selecting them in the browser and clicking the "right arrow" button that adds them to the right area. (Enable recursive collections if you want to see items from subcollections as well.)