The search menu contains a number of options including IDE contains a useful find in files option. When you open this dialogue with control f you a window opens as follows
In that window the box gives the text to search for and one may use the boxes and buttons to influence the search direction, case sensitivity, scope etc.
When you open the find in files tab you see
In using this, a double click on the box with three dots to the right of File path lets you browse for a path and the file mask lets you choose the file types to search. You can also exclude some files from the search using the lowest box. You then search for the text in the text to find box. After a search you get a box as follows.
You may now navigate using this box. Clicking on a red line opens the file identified. Clicking on a black line opens the file and moves the cursor to the particular line.