Hello Hanna,
... and welcome to our forum.
You can´t hide a group/table with managed code. Unfortunately you will not be able to use the same object model as you did while working in Visual Studio Windows Applications. An object has absolutely no formatting of display attributes, this is because XML is strictly data. To disable, hide, change color, or apply other formatting instructions to a control in your form you will have to use conditional formatting. To do this, double-click the control, click the Display tab, and then click the Conditional Formatting button. From here you can add rules to change the way your control is viewed. To be able to disable the node by code you will have to follow this process:
1. Create a text field and name it "field1Enabled".
2. Add conditional formatting on the field1 control that says to disable the control whenever the "field1Enabled" node is set to FALSE.
3. In your code, set the "field1Enabled" node to true or false corresponding with whether or not you want to enable or disable the control.
Hope that helps
Regards,