If there is - in the middle of [Column2], you can use below formula:
=IF([Column1]="Sweden",IF(ISERR(SEARCH("-",[Column2],1)),[Column2],REPLACE([Column2],SEARCH("-",[Column2],1),1,"")),[Column3])
Note:
- Sometimes comma(
,) does not work in formula (I am not sure but it is based on something language or regional settings on your site). So in that case use semicolon(;) instead of comma(,).
Same formula with ; separator:
=IF([Column1]="Sweden";IF(ISERR(SEARCH("-";[Column2];1));[Column2];REPLACE([Column2];SEARCH("-";[Column2];1);1;""));[Column3])
Update from comments:
Use below formula to show the empty calculated field if Column1 or Column2 is empty:
=IF(OR(ISBLANK([Column1]);ISBLANK([Column2]));"";IF([Column1]="Sweden";IF(ISERR(SEARCH("-";[Column2];1));[Column2];REPLACE([Column2];SEARCH("-";[Column2];1);1;""));[Column3]))