Between Bitcoin and USD, their correlation operates inversely. In simpler terms, when investors flock to a strengthening asset, let's say the asset gaining strength is USD, the interest in alternative assets like Bitcoin tends to decrease. This triggers selling pressure that significantly impacts prices. Naturally, investors have to decide which asset is more stable, meaning the one that's gaining strength at that time.
However, in certain instances of Bitcoin's price movement, things don't always unfold as anticipated. For instance, during a global economic crisis, people seek out a Safe Haven Asset. As of now, I would place gold at the top tier of Safe Haven Assets. Consequently, both USD and BTC might experience panicked selling.
I think that it is not entirely correct to compare dollar and bitcoin, because it have a lot of serious differences. For example, the well-known limited and endless emissions. Also, although bitcoin was conceived as a means of exchange (electronic money), at the current moment (most likely in the future it will be the same) it is a means of accumulation (wealth, value), while the dollar is a means of exchange (traditional money) .
There is a trend when investors, under market pressure, change their behavior strategy from investing in btc and usd, but most often, none of them plans to keep their investments in dollars for a long time, because this devalues their wealth due to inflation. That is, the dollar is a safe haven during a market storm, after which investors still rush to the means of accumulation (btc, gold, etc.).
Investors don't necessarily choose the asset that is gaining more power. It may be enough for them that the asset weakens less compared to other assets in order to avoid losses.
Gold has traditionally been considered a safe-haven asset, but now there are alternatives in the form of digital gold. Trends change and investors may switch to new forms of assets.