A deflector assembly, comprising: an upper deflector arranged within a main bore of a wellbore and defining first and second channels that extend longitudinally through the upper deflector, wherein the second channel exhibits a width greater than a width of the first channel; and a lower deflector arranged within the main bore and spaced from the upper deflector by a predetermined distance, the lower deflector defining a first conduit that communicates with a lower portion of the main bore and a second conduit that communicates with a lateral bore, wherein a bullnose assembly (402a, b) includes a bullnose tip coupled to a distal end of a body of the bullnose assembly, the bullnose tip exhibiting a first diameter (410a, b) larger than the width of the first channel and smaller than the width of the second channel and the body exhibiting a second diameter (412 a, b) smaller than the first diameter and also smaller than the width of the first channel, such that the bullnose tip is unable to extend through the upper deflector via the first channel but is able to extend through the upper deflector via the second channel, and, when the length of the bullnose tip is less than the predetermined distance, the body is configured to be received within the first channel upon exit of the bullnose tip from the second channel as the bullnose assembly is advanced and the bullnose assembly is directed into the first conduit, and when the length of the bullnose tip is greater than the predetermined distance, the bullnose assembly is prevented from moving laterally toward the first conduit as the bullnose assembly is advanced and the bullnose assembly is directed into the second conduit and the lateral bore, wherein the upper and lower deflectors are configured to direct the bullnose assembly (402a, b) into either the lateral bore or the lower portion of the main bore based on a length of the bullnose tip of the bullnose assembly as compared to the predetermined distance. an upper deflector arranged within a main bore of a wellbore and defining first and second channels that extend longitudinally through the upper deflector, wherein the second channel exhibits a width greater than a width of the first channel; and a lower deflector arranged within the main bore and spaced from the upper deflector by a predetermined distance, the lower deflector defining a first conduit that communicates with a lower portion of the main bore and a second conduit that communicates with a lateral bore, wherein a bullnose assembly (402a, b) includes a bullnose tip coupled to a distal end of a body of the bullnose assembly, the bullnose tip exhibiting a first diameter (410a, b) larger than the width of the first channel and smaller than the width of the second channel and the body exhibiting a second diameter (412 a, b) smaller than the first diameter and also smaller than the width of the first channel, such that the bullnose tip is unable to extend through the upper deflector via the first channel but is able to extend through the upper deflector via the second channel, and, when the length of the bullnose tip is less than the predetermined distance, the body is configured to be received within the first channel upon exit of the bullnose tip from the second channel as the bullnose assembly is advanced and the bullnose assembly is directed into the first conduit, and when the length of the bullnose tip is greater than the predetermined distance, the bullnose assembly is prevented from moving laterally toward the first conduit as the bullnose assembly is advanced and the bullnose assembly is directed into the second conduit and the lateral bore, wherein the upper and lower deflectors are configured to direct the bullnose assembly (402a, b) into either the lateral bore or the lower portion of the main bore based on a length of the bullnose tip of the bullnose assembly as compared to the predetermined distance.