private boolean getFieldForLocation(ListingField field, int fieldIndex) {
		FieldFactory ff = field.getFieldFactory();
		FieldLocation floc = ff.getFieldLocation(field, BigInteger.ZERO, fieldIndex, startLocation);
		if (floc == null) {
			return false;
		}

		if (!doSearchField(ff.getFieldName())) {
			return false;
		}

		// now determine where to start searching within the string
		currentFieldIndex = fieldIndex;
		startIndex = field.screenLocationToTextOffset(floc.getRow(), floc.getCol());
		return true;
	}
Returns the number of fields used in the match.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/searchtext/ListingDisplaySearcher.java