I will post my solution here. it may help to someone. 

import {Directive, Host, Inject, Input, OnDestroy, OnInit} from '@angular/core';
import {EditorComponent} from '@progress/kendo-angular-editor';
import {ToolBarDropDownButtonComponent} from '@progress/kendo-angular-toolbar';
import {Subscription} from 'rxjs';
import {DOCUMENT} from '@angular/common';
import {EditorInserterItem} from '@core/models/editor/editor-inserter-item';

@Directive({
  // tslint:disable-next-line:directive-selector
  selector: 'kendo-toolbar-dropdownbutton[kendoEditorInserter][items]"'
})
export class KendoEditorInserterDirective implements OnInit, OnDestroy {
  private subscriptions: Subscription = new Subscription();

  @Input() items!: EditorInserterItem[];

  constructor(
    private dropdown: ToolBarDropDownButtonComponent,
    @Inject(DOCUMENT) private document: Document,
    @Host() private editor: EditorComponent
  ) {
  }

  ngOnInit(): void {
    this.dropdown.textField = 'text';
    this.dropdown.data = this.items;
    this.subscriptions.add(
      this.dropdown.itemClick.subscribe((result: any) => {
        if (result?.value) {
          this.editor.exec('insertText', {text: result.value});
        }
      })
    );
  }

  ngOnDestroy(): void {
    this.subscriptions.unsubscribe();
  }
}

<kendo-toolbar-dropdownbutton text="Placeholders" kendoEditorInserter [items]="items">
</kendo-toolbar-dropdownbutton>