declare @xml xml
set @xml  = 
'<Root>
	<rows country = "ru" warehouse = "store1"  group_suplly = "АПСК"> <stock>1</stock> </rows>
	<rows country = "ru" warehouse = "store1"  group_suplly = "АПСК"> <stock>2</stock> </rows>
	<rows country = "ru" warehouse = "store2"  group_suplly = "АПСК"> <stock>1</stock> </rows>	
	<rows country = "ru" warehouse = "store2"  group_suplly = "АПСК"> <stock>3</stock> </rows>	
	<rows country = "ru" warehouse = "store3"  group_suplly = "АПСК"> <stock>1</stock> </rows>	
	<rows country = "ru" warehouse = "store3"  group_suplly = "АПСК"> <stock>5</stock> </rows>	

</Root>'

select 
		 Node.Data.value('distinct-values(@warehouse)', 'varchar(10)')
		,Node.Data.value('sum(//rows[@warehouse = "store1"]/stock)', 'float')
		,Node.Data.value('sum(//rows[@warehouse = "store2"]/stock)', 'float')
		,Node.Data.value('sum(//rows[@warehouse = "store3"]/stock)', 'float')
from @xml.nodes('//Root/rows') Node(Data)