GlideThumbnail.kt

// With thumbnail url
Glide.with(context).load(url)
        .thumbnail(Glide.with(context).load(thumbUrl))
        .apply(requestOptions).into(imageView)

// Without thumbnail url

// If you know thumbnail size
Glide.with(context).load(url)
        .thumbnail(Glide.with(context).load(url).apply(RequestOptions().override(thumbSize)))
        .apply(requestOptions).into(imageView)

// With size multiplier
Glide.with(context).load(url)
        .thumbnail(0.25f)
        .apply(requestOptions).into(imageView)