Can I select like this? value from an element, whose parent element is diferent (ie value of an element from different context) ? OR do I have to select elements from respective parent element only ?
The <xsl:value> element doesn't care that it's a child of some other element which refers to something else. The only relevance of the <xsl:template> element which contains it is that it sets the context node. You can use any XPath element you like in the "select" element of <xsl:value>.