Google decides the Map Pack with three signals: how close you are to the searcher, how relevant your profile is to what they typed, and how prominent your business looks across the web. Only one of those is fixed.
Relevance is a content problem
Most Thai businesses pick one broad category and stop. Adding precise services, Thai and English descriptions, and real product entries gives Google far more to match against. We routinely see listings move into the Top 3 from category and service work alone.
Prominence is earned off your profile
Consistent citations, local backlinks, and a steady review pace tell Google your business is real and active. A burst of twenty reviews in a week is worth less than two reviews a week for ten weeks.