Two other ways:
1. Assign a hotkey to Dashboard. You can invoke Dashboard by pressing that key and also dismiss it by pressing the key again.
2. Click the arrow at the right of the screen when you are in Dashboard.
OS 10.14.3, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365