get design attribute value on same page to another component in lwc

Question

here is design atrribute @api parentcls and childcls i m trying to fetch these design attribute in another component on same page i tried constructor too but didnt get value on load

@api parentcls='';
@api childcls='';

connectedCallback(){
    console.log('connectedcallback',this.parentcls); //value getting
    console.log('connectedcallback',this.childcls); //value getting 
    fireEvent(this.pageRef, 'parentclass', this.parentcls);
    fireEvent(this.pageRef, 'childclass', this.childcls);
}

in another component of same page

connectedCallback() {
    registerListener('parentclass', this.parentcss, this);
    registerListener('childclass', this.childcss, this);
}