I have Open image in Photoshop cc. as you can see in the background only one layer, we have to convert this layer to smart object. just go on Filter menu at top and select option convert for Smart Filters:
When you select this option for the first time, you will see this below warning box
After this convert layer into a smart object . now have layer converted in to smart object, which i can show you a lettle smart object icon in the red circle on the right corner of the layer view.
Step 2: Apply Filter to the Smart Object
Go to Filter menu on the menu item and select Sharpen, and then select Unsharp Mask
This will show Unsharp Mask dialog box. And i will make some changes on the settings:
And we can see in the Layer palettes:
On the beneath smart object layer, we have area that says "Smart Filter", that indicating we have at least one smart filet applied on the object.