Matrix Block Tabs
You can split up the fields of each individual Matrix block. Separate the block fields into tabs, making it easier to organize relevant fields.
When configuring the Matrix field's block groups, you'll notice a gear icon beside each block type.
Clicking the gear icon will open a new layout editor, similar to what you were just working with. However, this new layout editor will control which block fields will be organized into tabs.
Closing the tab layout editor will bring you back to the block groups layout editor.