How can I recover the purchases done in another country store?

Correct. Changing stores will make purchases from the previous store unavailable until you change back to that store.

Change your iTunes Store country or region - Apple Support

• You won't see the items that you purchased from the previous country’s store in your Purchased section.
• You won’t see the items from your iCloud Music Library that you matched, uploaded, or added from the previous country’s store.

i.e Purchases are not removed, they are simply only available while using the country store from where they were purchased.

Changing countries or regions wipes out the Purchased list from the previous store. However, if any of the same content, say an app, is also sold in the new store, you can redownload it or update it. Go through the motions of buying it in the new store and in the final steps of the sale the Mac App Store will realize that you have previously bought this content and offer to download/update it for free.

Late 2012 Mac mini, OS X El Capitan 10.11.5 beta 3;  Watch, 38 mm silver AL, Watch OS 2.1; iPad Air 2 & iPhone 6+, iOS 9.3.2 beta 3;  Apple Airport Express