On the Mac, CMD-F opens the field to search the currently selected dot.

On iOS the process is a little less straightforward. Here are the steps:

1. Select a word inside a dot and tap to bring up the Context menu with "Cut, Copy, Paste, >"
2. Tap the caret at the end of the context menu
3. Tap Find Selection

Now you can either find that selected word or change the term/word you are looking for to something else to find it within the dot.

To do this a little quicker you could insert the cursor at the top of the dot and type the text you want to find, select it and then follow these steps.