Is the symbol text such as from a dingbat font or an image?
When you overlayed text on top of the button, did you try grouping the text field with the button? or using button set up to turn the text field into your button with the image of the button simply displayed in the background behind it?
Its any text, be it a dingbat font glyph, or a unicode symbol, or a standard alpha-numeric symbol. I have tried doing the other things you mention as well, but the problem remains where the object (regardless if its a button or text field) does not appear to have a way to slightly reposition the text contained within it. I just need to nudge it around a little, just as can be done by overlaying the text field and then moving it around; however, this has its limitation in WebDirect views.
What version of FM are you using? If your using 13, what them?
I am using Filemaker Pro 13 (standard).
I don't think that you understood my suggestion.
Make the field your button. Place a graphic object that looks like a button behind it. Now you can nudge the Field that's also a button around with your arrow keys to make slight adjustments to the position of the text relative to the graphic object placed behind it.
Put a graphic object "button" on your layout. Put your field on top of it. Make the same adjustments as above. Then select both graphic object and text field and use Button Setup to group these objects into a button.