I am use mat tree node for get some selection node from user like this:

export class SelectDataComponent implements OnInit {

    @Output() selectedList=new EventEmitter<any[]>();
    @Input() exportMode: boolean;
  private _transformer = (node: DeviceNode, level: number) => ({
    expandable: !!node.children && node.children.length > 0,
    id:node.id,
    name: node.name,
    level: level,
    });
   treeControl = new FlatTreeControl<ExampleFlatNode>(
    node => node.level, node => node.expandable);
   treeFlattener = new MatTreeFlattener(
    this._transformer, node => node.level, node => node.expandable, node => node.children);
   dataSource = new MatTreeFlatDataSource(this.treeControl, this.treeFlattener);
   checklistSelection = new SelectionModel<ExampleFlatNode>(true /* multiple */);
    tree: any;

   constructor(private _propertyService: PropertyService) {
    }


   hasChild = (_: number, node: ExampleFlatNode) => node.expandable;
   ngOnInit() {
              this._propertyService.getTreeNodes().subscribe((respP)=>{
             this.tree=JSON.parse(respP.data);
            //this.tree =TREE_DATA;
            this.dataSource.data=this.tree;
        });



       };

       todoItemSelectionToggle(node: ExampleFlatNode): void {
        this.checklistSelection.toggle(node);
        const descendants = this.treeControl.getDescendants(node);

        this.checklistSelection.isSelected(node)
          ? this.checklistSelection.select(...descendants)
          : this.checklistSelection.deselect(...descendants);

        descendants.every(child =>
          this.checklistSelection.isSelected(child)
        );

      }
      todoLeafItemSelectionToggle(node: ExampleFlatNode): void {
        this.checklistSelection.toggle(node);

        const a=of(this.checklistSelection.selected);

      }
      public sendToDataList(){

        if (this.checklistSelection.selected.length===0) {
            console.log('error');
        }
        else
        {
        const b=this.selectedList.emit(this.checklistSelection.selected);
      
        }
    }
    public clearList()
    {
        this.checklistSelection.clear();
    }
    }

How can I deactivate another node by selecting one node? That is, if 'A' is selected, checkbox 'B' will be disabled

My goal is to impose data selection constraints that node 'A' and 'B' are not selected at the same time.