When using NSSearchField , secondary NSTableView looses focus and do not update simultaneously - objective-c

Question

I am using core data binding in cocoa app. My app has three NSTableViews bound to there NSArrayControllers in relationship such that if first table is selected, relevant data using Core data relationship is shown in the other two tables.
I have hooked NSSearchField to first NSArrayController. The problem is when search begins the other two tables do not remain in sync with the first one.They show nothing at all.
The other two tables only shows content when first one if clicked by user.
How can I make all three NSTables update simultaneously when search occurs.

Answer 1

So, I have this solution which works, I would like to know if this can be improved further.
Since when search starts the first NSTableView's selection is lost and hence the connected tables too, although the table is updated correctly showing filtered value. I am setting self as observer for change is NSArrayController selectedObject.
-(void)awakeFromNib{
[super awakeFromNib];
[_firstArrayController addObserver:self forKeyPath:#"selectedObjects" options:NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld context:NULL];
}
Now I am observing for changes and if selected object do change and if NSSearchField is the one changing it, programatically select NSTableView first row
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)
object change:(NSDictionary *)change context:(void *)context
{
NSResponder *firstResponder = [[NSApp keyWindow] firstResponder];
if ([firstResponder isKindOfClass:[NSText class]] && [(id)firstResponder delegate] == _searchField) {
NSIndexSet *indexSet = [NSIndexSet indexSetWithIndex:0];
[_authorTable selectRowIndexes:indexSet byExtendingSelection:NO];
}
}
Since when filtering using NSSearchField, the first object is what the most relevant, hence I am setting selection to row 0.