You can set a different server with
addressBookDb="ServerName!!names.nsf"
before the database name devided by "!!"
<xe:namePicker id="namePicker1">
<xe:this.dataProvider>
<xe:dominoNABNamePicker addressBookDb="ServerName!!names.nsf">
</xe:dominoNABNamePicker>
</xe:this.dataProvider>
</xe:namePicker>