Gets a little confusing now that there are a number of LDS/familysearch databases available and which can give you slightly different results sometimes

IGI (International Genealogical Index) which is often mentioned is from the original search screen here
www.familysearch.org/Eng/Search/frameset_search.asp?PAGE=igi/search_IGI.asp&clear_form=trueNot sure which you are using. There is also this link, which relates to the newer recently released site
www.familysearch.org/#startFor Scotland, I find the IGI in general much more effective for me.
To do a parent search for Scotland on the IGI screen, just put in the full names (first and surnames) for father and mother on the right hand side. Then British Isles/Scotland. You normally get just one couple's children. If you feel you are getting to many results, you can add time filters and county options (take care with the county option as people did move around and you may miss some entries).
As always with IGI, check the 'message' section at the bottom of each entry to make sure that what you are looking at is actual extract from official statutory or old parish registers. This will be clearly stated. Alternatively, the entry may show as an LDS member submitted entry which you need to confirm elsewhere as these entries can be plain wrong and misleading.
Monica