If you enter one search term at a time into the search box, you will see that Emtree terms appear below the box. You can accept (by clicking them) or not. When you do accept the Emtree term, the word(s) will appear in the search box within single quote marks.
Note the default settings underneath the search box. "Search as broadly as possible" is checked; Embase will search for results using both keywords & Emtree terms. Uncheck this box if you need to narrow your search to citations that are indexed only.
Below, you can set a publication date limit. Either accept "all years" by doing nothing or uncheck that box & choose years from the dropdown lists.