As you can see in photo in Type picklist field when i select salesforce sObject only that time i'm able to select Sobject type picklist otherwise it's disabled. enter image description here
like this other filed is selected or none then sObject Picklist field is disabled we can't select it. enter image description here
Just added this on controller
onChageType:function(component){
var val = component.get("v.type");
// console.log('type',val);
if(val == 'Salesforce sObject'){
component.set('v.isActive',false);
}
else{
component.set('v.isActive',true);
component.set("v.selectSojbect",'');
}
},