There were certainly organizational and command ranks in samurai armies. Samurai existed for hundreds of years, and so the way armies were organized and the name used for each type of person changed throughout the ages. For the time around 1600, see here for an idealized version of mobilized forces with the different roles in the army, and here and for the social status of the individual men.

Keep in mind that these differed from modern military ranks in an important way: they were tied to the wider socio-political structure much more than in modern armies. Today, whether or not you enter the army by volunteering or being drafted, initially the only difference is officers and enlisted men with the difference being officers have gone through military academy or post-secondary education so are expected to lead, while enlisted men are expected to fight. Afterwards both start at the bottom of their respective group and move up the ranks based on experience or deeds. Once demobilized, their official ties end. While a private may have befriended his sergeant and look up to him, take his advice, and go out for beer together even after the war was over, the two may also return to being strangers from different places and fall out of contact, and certainly the sergeant has no legal right to order this private around when they exit the armed forces. This was not the case in Japan (or really in much of the world) before modern times. As the government did not have a "recruitment office" mobilization was done by people on top giving the order to their subordinates to get their men. Said subordinates would in turn go to their subordinates and give the same order, and this would continue all the way down. Without modern recruitment and mobilization bureaucracy, the natural way to mobilize then would be for men to bring people they know: the lord would bring his vassals and retainers, the common samurai would bring his "servants". The lower ranks all already work for the upper rank in other manners. The lord bringing his personal guards, squires, and pages and his vassals were already important members of his clan, quite possibly his relatives, that were members of his government. The small samurai would be bringing people like his brothers and cousins, his servants (often literally) or the notable of a village he rules over. In times of peace these men would be doing other duties in the same group. A samurai in peace might be in charge or policing the area of a city and those men he would bring with him to war would also be working under him in peace, in this case helping him with administrative duties or actually patrolling the streets. As such, these "ranks" were as much social as they were military. The boss, a wakatō's bushi, a samurai's bugyō, a karō's daimyō were much more than one's commander in the army. He was the boss for life in general.