//add _launchCrossApp() function to the base controller and invoke as below
const semanticObject = "MyCustomApp";
const semanticAction = "display";
let mParams = {};

mParams["myParameter"] = "myValue";

this._launchCrossApp(semanticObject, semanticAction, mParams);

// the function
_launchCrossApp: function _launchCrossApp(semanticObject, semanticAction, mParams) {
  const oCrossAppNavigator = sap.ushell.Container.getService("CrossApplicationNavigation");

  // generates a hash for the Fiori Launchpad to follow
  const hash = (oCrossAppNavigator && oCrossAppNavigator.hrefForExternal({
    target: {
      semanticObject: semanticObject,
      action: semanticAction
    },
    params: mParams
  })) || "";

  // navigates to the new hash
  oCrossAppNavigator.toExternal({
    target: {
      shellHash: hash
    }
  });
}