1、取navigationCtroller中的Controllers
NSArray * ctrlArray = self.navigationController.viewControllers;
2、取出后，执行，
[self.navigationController popToViewController:[ctrlArray objectAtIndex:0] animated:YES];
既可。（这里的objectAtIndex，根据情况而定）

备注：
NSArray *ctrlArray = self.navigationController.viewControllers;

for (UIViewController *ctrl in ctrlArray) {
    
    NSLog(@"ctrl ---- %@", ctrl);
    
}