How to Change the property of Control in fragment in sap ui5

Hello, iam developing one application on sap ui5.

i have created a view in which iam using two fragment First fragment is for displaying the data and then as Edit Mode.when ever user click on Edit Mode ( which is second fragment ) .but i want to show some controls For exm : - I have four Input controls in Edit fragment mode.but i want to show the controls on based on some conditions.like some time two controls are in editable mode ,and others are in display mode

this.byId().setVisible(false);

issue is this property is Undefined.

Regard

Shardul Pandey