How to get one form controls in other form in D365

How to get one form controls in other form in D365    

FormRun formRunloc;

formRunloc = this.formRun().args().caller();

 FormStringControl  nameloc =   formRunloc .design().controlName(formControlStr(PurchTable,Name1));

FormStringControl  nameloc1 = formRunloc .design().controlName(formControlStr(PurchTable,Description));